Gold Beating: How Gold Leaf is Made

Dating back to the days of the pharaohs, 5000 years ago, men have hammered strips of gold into thin sheets of gold leaf in a manufacturing process known as gold beating. While the tools have changed through the centuries, the basic process remains the same. In the days of the ancient Egyptians, gold beaters used stones. Later metal hammers with convex heads were introduced. 

In ancient times, the Romans beat gold to the width and length of four fingers. This dimension is very close to the dimensions of gold leaf sheets produced today, which is 3-3/8″ × 3-3/8″ (8.6 cm × 8.6 cm).

Types of Gold Leaf

Gold leaf is a very thin sheet of real gold, hundreds of times thinner than a sheet of paper. The gold used to make gold leaf is mixed with other metals, either to change some of its physical properties or to alter its colors. 24 karat gold leaf is about 99.9% pure gold. The remaining .1% is typically silver and copper. (A karat is the unit of measure used to describe the purity of the gold. One karat equals 1/24 of the gold content.)

If you know any experienced gilders you probably have heard them use terms such as moon gold, lemon gold, and white gold. These are very specific terms, describing specific colors of real gold leaf of different karats. Moon gold is 22k, comprised of 92% gold. Lemon gold is 18k, or 75% gold. White gold is generally 12k consisting of 50% gold and 50% silver. These are just some of the many different gold leaf products available to gilders.

Another gold leaf term that you may have heard is glass gold. This type of high quality gold leaf product exhibits fewer surface imperfections and pinholes and is used for glass gilding. Double gold leaf is a heavier product, being about 10% to 20% thicker than standard gold leaf.  

The Gold Beating Process

The gold beating process changed very little over thousands of years. Whether gold beating is done by hand or by machine, the sheet is formed using some type of hammer and anvil. In Europe, the anvil was traditionally a block of granite or marble. The Egyptians beat gold into thin sheets using stones. These stones were replaced with cast iron hammers. In some countries in the Far East gold beating is done with wooden mallets. In the modern shop, gold beating is mechanically done with a tilt hammer. Ox intestine and parchment have also been replaced by mylar.

During the Industrial Revolution, gold beating machines were invented to mimic the gold beaters pattern of hammer strokes. As the machine pounds away the operator must rotate the packet. For some manufacturers, however, the final steps in making gold leaf still require beating by hand. 

Whether gold beating is done by hand or by machine, the sheet is formed using some type of hammer and anvil. In Europe, the anvil was traditionally a block of granite or marble.

As craftsmen improved their techniques of goldbeating, gold leaf became thinner and thinner. Today a sheet of gold leaf is about .1 µ to .5µ, which is 120 times thinner than the human hair. It is so thin that if you could hold it up to a light it would appear transparent. Of course, if you held real gold leaf in your hands, it would likely fall apart.

To achieve this thickness requires multiple steps and great skill. To master this skill typically takes at least ten years of apprenticeship. In the United States very few of these craftsmen still remain today. It is literally a dying art.

To make gold leaf, a thin bar of the malleable metal is rolled to a ribbon of metal about 25µ or approximately 1 mil. This is the thickness of aluminum foil. The ribbon of gold is cut into small squares about 1.3” x 1.3”. These squares of gold are placed between sheets made of the intestinal membrane of an ox and beaten. 

This gold beating process again reduces the thickness of the gold and at the same time increases the size of the sheet to a four inch square. This square sheet is cut into four pieces and subsequently placed between sheets of parchment and beaten again.

As a gold beater hammers the cutch, which is the packet that holds the sheets of gold, his hammer strokes follow a very precise pattern. In hammering the packet of gold, the gold beater also rotates it. This process ensures that the gold is stretched equally in every direction, also ensuring that the gold leaf is a uniform thickness.

Gold leaf comes in books of 25 sheets. Thin backing paper separates one loose leaf from another. Pictured here is patent leaf, which is gold leaf material that is stuck to the backing paper.

Gold leaf comes in two forms: loose gold leaf and patent gold leaf. Loose leaf means that the gold leaf is interleaved between very thin sheets of rouged tissue paper. This rouged paper has been dusted with ferrous oxide dust, which prevents the leaf from sticking to it. To transfer the gold leaf, the gilder uses a gilder’s tip brush.

Patent leaf has been pressed onto one side of the tissue paper that separates the individual leaves of gold. With the gold being lightly adhered to the paper, the gilder can easily transfer the gold leaf to the sized application surface.  The gold usually stays stuck to the sheet unless the paper dries out. Too much moisture in the paper is also a problem. High humidity can increase the bond the gold to the paper, making transfer difficult. To prevent these problems, some gilders store their books of patent leaf in a plastic container in their refrigerator.  

About Gold Leaf and Metal Leaf. Gold leaf is available at some sign supply distributors. A book of gold leaf contains 25 leaves, each of which is 3-3/8” x 3-3/8”. Each book contains enough gold leaf for you to gild approximately two square feet. Separating the leaves of loose gold leaf are sheets of tissue paper. Patent leaf is gold leaf, which is bonded to the tissue paper.

“Patent leaf is easy for the beginner to use,” says Joe Balabusczko, who, for much of his career as a sign painter in Chicago, specialized in gilding. “Patent leaf is no substitute for loose leaf.” Balabusczko explains that you can work much faster with loose leaf. What’s more, you can only use loose leaf for glass gilding and traditional water gilding applications. Experienced gilders also believe that you can achieve a more brilliant gild with loose leaf. The reason that patent leaf does not produce as glossy of a finish is that the surface of the gold picks up the impression of the paper. Nevertheless, if you haven’t worked with gold leaf before and you are working in a flat, smooth substrate, patent leaf is much easier for the newbie to work with than loose leaf.

Goldleaf photo attribution. By Juangonzalez64 at English Wikipedia (Transferred from en.wikipedia to Commons.) [Public domain], via Wikimedia Commons. Juangonzalez64 grants anyone the right to use this work for any purpose, without any conditions.

At the beginning of the 20th century, most of the gold leaf was used to in the sign industry to gild glass windows and doors and to surface gild a variety of letters. Today, very little gold leaf is used for signage and has been replaced by vinyl graphics. Most of the gold leaf sold today is used to decorate picture frames, statues, domes of buildings and artwork. 

Glass gold is a high quality gold leaf product, which exhibits fewer surface imperfections and pinholes. Double gold leaf is a heavier product, being about 10% to 20% thicker than standard gold leaf. 

Of course, all that glitters is not gold. Real gold leaf is not to be confused with imitation gold leaf, which is called Dutch Gold, Schlagmetal or composition leaf. While imitation Dutch gold looks like the real thing, it is instead brass, comprised of 85% copper and 15% zinc. The shortcoming of this metal leaf is that it discolors.